docs: def show(self, imgs, ax=None):
          """ Visualize the persistence image
  
          """
  
          ax = ax or plt.gca()
  
          if type(imgs) is not list:
              imgs = [imgs]
  
          for i, img in enumerate(imgs):
              ax.imshow(img, cmap=plt.get_cmap("plasma"))
              ax.axis("off")